Locale, language problems on KDE

strong textHello,

I ran into a problem: at a certain point, the locale flew off. For the time being, I put up with the fact that some programs swear, but only until LibreOffice became one with them. Now when I insert Russian text into it (insert “only text”, without formatting), it turns them into strange characters and question marks. However, if I just write something in it in Russian, then everything is OK. In the settings of its language I set wherever possible the Russian language. I put different packages, fresh and still — nothing helped.
Setting up locales, as written in archwiki and other official sources — all in vain. Error after error.

For example, locale outputs:
locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannot set LC_MESSAGES to default locale: No such file or directory
locale: Cannot set LC_ALL to default locale: No such file or directory
LANG=en_US.UTF-8
LC_CTYPE=«ru_RU.UTF-8»
LC_NUMERIC=ru_RU.UTF-8
LC_TIME=ru_RU.UTF-8
LC_COLLATE=en_US.UTF-8
LC_MONETARY=ru_RU.UTF-8
LC_MESSAGES=«ru_RU.UTF-8»
LC_PAPER=ru_RU.UTF-8
LC_NAME=ru_RU.UTF-8
LC_ADDRESS=ru_RU.UTF-8
LC_TELEPHONE=ru_RU.UTF-8
LC_MEASUREMENT=ru_RU.UTF-8
LC_IDENTIFICATION=ru_RU.UTF-8
LC_ALL=

locale-a:
[leo@pc ~]$ locale -a
locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannot set LC_MESSAGES to default locale: No such file or directory
locale: Cannot set LC_COLLATE to default locale: No such file or directory
C
POSIX

locale-gen:
[leo@pc ~]$ locale-gen
Generating locales…
en_US.UTF-8…failed to set locale!
[error] cannot open locale definition file `en_GB’: No such file or directory

localectl for any language locales:
[leo@pc ~]$ localectl set-locale LANG=en_US.UTF-8
Failed to issue method call: Locale en_US.UTF-8 not installed, refusing.

In locale.gen these lines uncommented:
ru_RU.UTF-8 UTF-8
en_US.UTF-8 UTF-8

Tried to edit locale.conf – didn’t help.

In the system settings, the same locales as in locale.gen installed.

Perhaps there is something in this thread that can help: Man: can't set the locale; make sure $LC_* and $LANG are correct, with these notes to this thread:

There are number of reports on kcm_language, some just requesting clarification on usage.